Alarm gauge



1,689,830 O. W. HEISE ALARM GAUGE Oct. 30, 1928.

' Filed Aug. 26, 1925 2 Sheets-Sheet 1 .sfo

'blinf oct. 3o, 192s, 1,689,830

O. W. HEISE ALARMGAUGE lmed Aug. 26, 1925 2 sheets-sneer. 2

Patented Oct. 30, 1928.

UNITED STATES PATENT oFFlcE oTTo w. nEIsE, or EBIDGEPOET, CONNECTICUT, AssIGNoE, EY MEsNE ASSIGNMENTS,

2O CONSOLIDATED ASHCROFT -HANCOCK COMPANY, OF NEW YORK,N. Y.,

BATION DELAWARE.

A CORPO- ALARM GAUGE.

application ma August-26, 1925. serial N0. 52,706.

the lnotor which drives the pressure produc-l ing pump or indirectly to operate a-solenoid or other electro-magnetic means which in turn operates the motor switch or a valve or other device for regulating or varying the iiuid pressure in the system vto be controlled.

Such devices also frequently embody means for closing an alarm or signal circuit When'the main circuit is broken and are usually provided with a pressure indicator or gauge for visual observation of the pressure.

In devices of the abme character it is essential for accuracy of control that the switch be held closed in a positive and reliable manner until the predetermined pressure has been fully attained, and then suddenly rei leased.

Since the pressure responsive device, for example a Bourdon tube, which is employed as the motive means for breaking the circuit usually moves to a very slight extent in responding to pressure changes and is capable of exerting only a relatively small amount of force, it is also necessary that the switch retaining means be easily releasable; moreover, as under some conditions of use the switch is called upon to handle a comparatively heavy current, for example when it directly controls the current of the pump motor, it should be capable of controlling `such a current without difficulty and yet Without necessitating such increase in the weight r frictional resistance of the movable parts of'the switch as to prevent its ready actuation by the pressure responsive element; while furthermore the switch contacts should be soarranged as to insure completion of the circuit when. the switch is closed since otherwise disastrous results might ensue.

In accordance with the present invention I have provided latch means which positively locks the switch in closed position` but which offers but slight resistance to release of the latch by the pressure responsive devices,

' controller,

while at the same time providing for the rapld and wide opening of the switch when the latch is released; I also provide ready means for closing the switch and resetting the latch after the pressure in the system has receded from the critical point. Moreover,

Il provide for automatically breaking the arc which tends to form between the contact surfaces of the switch when it is opened, thus avoidlng rapid burning of the contacts when employing heavy current. I also provide for relative sliding or rubbing of the contact surfaces in closingthe switch so as to provide clean contact surfaces. to provide for such relative movement of the contact surfaces has a secondary function, in that it permits ready re-engagement of the latch elements without necessitating nice adjustment of the parts. These and. other minor improvements,` including means for adjust-ab] y determining the pressure at which the switch shall open are illustrated by way of example in a preferred embodiment in the accompanying drawings wherein:

Fig. 1 is a. front elevation of my improved certain parts being broken away; a side elevation viewed from the side of t-he device as shown in Fig. 2 is right hand Fig. 1 l l Fig. 3 isa section substantially on the line 3-3 of Fig. 2; f

F ig. 4 is a1 diagram illustrating certain electrical connections employed in the operation of the controller; I

' F ig. 5 is a section substantially on the line 5-5 of Fig. 2 but to somewhat larger scale and showing the switch contacts closed; and

Fig. 6 is a view generally similar to Fig. 5 but showing the main switch contacts open and the alarm circuit contacts closed.

Referring to the drawings the numeral 1 designates a casing of the general type employed in gauges and similar instruments,

The mea-ns employed and which is open at both front and back.

'of the casing. This sleeve furnishes protection for a plurality of electrical conductors 5, 6 and 7 which enter the casing through this through which the conductors pass.

The stem 2 is connected to a bracket 8 within the casing which carries a pair of oppositely directed Bourdontubes 9 and 10 respectively. The bracket 8 also carries a movement frame 11 supporting the usual gauge movement 12. The Bourdon tube 9 is furnished with a rigid arm 13 at its end which is connected by means of a link 14 to the segmezitglever 15 of the'gauge movement. The indexfastaff 16 of the gauge movement carries thelindex needle or pointer 17 which cooperates with a scale 13 upon the dial plate 19. This dial plate 19 is enclosed within a glazed cap 20.

The free extremity of the Bourdon tube 10 is furnished with a rearwardly extending pin 21 which projects through an elongate opening 22 in'a partition 23, preferably of insulating material, dividing the interior of Athe ycasing into front and rear chambers respectively. The Bourdon tube and the gauge movement above described, are located within the forward chamber. The rear side of the rear chamber is closed by means of a removable glazed cap 24.

A brackt 23*L (Fig. 5) is attached to the rear face of the partition 23 and carries a pair of rearwardly'projecting pins 25 extending through an elongate slot 26 in a slidable carriage 28.. This carriage is guided by the pins so that it may slide in a substantially horizontal direction. A springj29, attached at one end to the bracket 23", bears at its other against the left hand end of the carriage 28,V

as viewed in Fig. 5, and thus yieldingly urges the carriage to the right. At its right hand end the carriage 28 is furnished with a contact member 27 forming one of the contacts .of

. v`the main circuit controlling switch. The end of the conductor 5 is secured to a binding post 30 carried by the partition 23 and this post in turn is connected by a. short flexible conductor 31 to the carriage 28. The carriage 28 being,

of metal, forms a suit-able electrical connection between the end of the conductor 31 and th contact 27.

A pivot pin 32 is secured to the partition l23 and supports a switch Vlever 33. This switch t lever is provided with a contact 3,4 which cooperates with the contact 27 to close the main electrical circuit. The switch lever 33 is provided with a short arm 35 to which one end 36 of a tension spring 37 is attached. The other end of this spring is secured to a pin 38 projecting from the partition 23 and the relation of the pin 38 to the pin 32 is such that when the switchcontacts are in engagement the line of pull of the spring lies closely adj a- I cent to the axis of the lever 33, but moves away from such axis as the switch contacts separatei The spring thus acts with an in- `\jecting bracket arm 43furnished with a slot which receives the grooved head 44 ci an adjusting screw 44. This screw has threaded engagement with1 a bracket 46 carried by the partition 23 and its slottedend 47 is disposed just inside of an opening 49 in the wall of the casing. This opening 49 is normally closed by means of a resilient cover plate 50 which may be swung to one side to admit a screw driver :for adjusting the screw 44a to swing the support 39 about the pin 40. The support 39 is furnished with an elongate slot 51 for the reception of a set screw 52 by means of which the support 39 may be permanently secured in adjusted position, if desired. The set"`screw,` when not' fully set up, provides a guidd. for the support 39 when being adjusted by means of screw 44a.

The support 39 is provided with a pivot pin 53 near its angle or bend 41 upon which is mounted a latch lever 54 of bell-crank type. The upwardly extending arm of this latch lever is connected by meansof a link 53 to the pin 2.1 projecting from the free end of the Bourdon tube 10 as above described. A- light spring 56 carried by wthe support 39 engages the upwardly extending arm of the bellcrank lever 54 and tends to swing the latter in a clockwise direction, as viewed in Fig. 5.

This bell-crank lever 54 also comprises a substantially horizontal latch arm 57 preferably provided with a curved cam surface 58 at its end, such surface terminating in an abrupt substantially vertical shoulder 59. The upper end of the switch lever 33 isalso preferably provided with a curved or cam sur- Aface 61 and with a flat face 60 constituting a retaining dog n adapted to engage the shoulder 59 of the holding latch 57. The elect'rical conductor 6 is connected to a binding post 62 which in turn is connected by a flexible conductor 63 to the switch lever 33 at a point near the pivot 32 of the latter. The switch lever, being of metal, forms a suitable conductor'between the switch contact 34 and the conductor 63. Adjustment of the support 39 about its fulcrum varies the length of the normal line of contact of the dog 60;1 with the shoulder 59.

A bracket 64 is secured to the switch lever 33 and a. resetting pin 65 is pivotally connected to the bracket 64. This pin liasses out through an opening 66 in the side wall of the casing and is furnished with a button 67 on its outer end for manual manipulation.

A pivot pin 68 projects from the partition 23 at the left of the carriage 28, as viewed in Fig. 5, and carries a barrier supporting lever 69. This lever preferably has a ben. at the point 70 and a downwardly inclined arm71 which is provided with a rearwardly overhanging lip 72 normally resting upon the toe 73 of a short arm 74 projecting from the switch lever 33. A light spring 75 tends to swing the lever 69 in a clockwise direction. The free extremity 76 of the lever 69 is provided with clam ing means for holding a barrier plate 77. 'llhis plate is bent to arcuate form, having the pivot 68 as its center of,curvature, and is so disposed that when the lever 69 I,is swung upwardly to the position shown in Fig. 6 this barrier plate is interposed between the contacts 27 and 34.

The switch lever 33 is provided upon its right hand side with a second contact 78 which is adapted to engage a fixed contact 79 carried by a bracket 80 projecting from the partition 23. A conductor 81 leads from the bracket 80 to a binding post 82 to which the inner end of the conductor 7 is attached.

Referring to Fig. 4, the conductors 83 and 84, indicated diagrammatically may be considered as the positive and negative wires leading from any suitable source of electrical energy as, for example,a dynalno or battery. One of these wires, for example, the wire 84 is connected directly to the conductor 6 and thus to the switch arm 33. The other wire 83 is connected by a shunt 85 to one terminal of an electro-magnetic device 86, such,

' for example, as a solenoid whose core. 87 is secured to a part, for example, a switch, which is to be controlled by the ope-ration of the improved controlling mechanism. The other terminal of the device 86 is connected by a wire 88 to the conductor 5. The wire 83 is'also connecte-d, if necessary through a suitable resistance R, with-a wire 90 leading to a. bell or other visual or audible signal 89. The other terminal of thissignal device is connected to theconductor 7.

It is assumed that the apparatus is to be employed for controlling an-electrical switch, which in turn controls the flow of current through a pump operating motor, and that suchl switch is connected to the core 87 -of t-he solenoid, and that the parts have initially been set as shown in Fig. and that the electrical switch is closed, and that the. pressure pump is operating. As the pressure rises the indicator needle 17 moves over the scale 18, thus indicating the rise in pressure. The parts, having beenproperly adjusted to open the contacts 27 and 34 at a predetermined pressure, the gradual movement of the Bourdon tube will, when the predetermined pressure has been reached, have swung the lever 54 about the pivot 53 until the shoulder 59 is disengaged from the dog 60a, whereupon the spring 37 swings the lever 33 to the right, separates the contacts 27 and 34, and brings the contacts 78 and 79 intoengagement. At the same time that the cont-acts 27 .and 34 separate, the barrier 77 is thrust into the space between them, thus extinguishing any arc which might form as they separate. The circuit is thus broken through the electromagnetic device 86, whereupon the core 87 drops either by its weight alone or assisted by a spring, andbreaks the circuit through the pump switch, thus stopping the pump and preventing further rise. in pressure in the system.

If now, before the pressure has substantially decreased, anyone should attempt to reset the controller by pushing in the button 67, the dog "L will not interlock with the shoulder 59 of the latch 57, since the latch 57 is still held in its elevated position and the circuit will only remain closed so long as the button 67 is held inwardly.

Since the alarm circuit is closed through the contacts 78 and 79 when the switch is opened,the alarm device will continuously function, giving visual or audible indication of the fact that the predetermined pressure has been reached or exceeded, so that the person in charge may take any such further steps as may be necessary toy prevent undue rise of pressure in the system. l

When the pressure has dropped belou,7 the predetermined point, the operator may push in on the button 67 and since the latch 57 will now have dropped, the surface 61 engages the surface 58 of the latch and cams the lach upwardly until the dog 60a is permitted to engage the shoulder 59. This movement of the lever 33 also permits the spring 75 to 'retract the barrier 77 from between thel contacts and pushes the contacts 27 and 34 into engagement. Since the Contact 27 may yield t0 some extent, the contact 34 mayl l Il() 59 without necessitating any extreme accuracy in adjustment of the parts. Moreover, sincethe. contact 34 swings in a circular are, while the contact 27 moves in a rectilinear pat-h, the contacts move slightly relatively to each other, substantially in the plane of their contacting faces, that is to say, they slip upon one another to a slight extent, and thus automatically clean ofi' oxide or other insulating matter which might accumulate upon their engaging faces. By repeatedly pushing the button 69 inwardly while the contacts 27 and 34 are in engagement, this cleaning action may be repeated toany desired extent.

By reason of the arrangement of the springl 37 it exerts but slight force upon the latch lever 33 when the contacts 27 and 34 are engaged and thus there is little pressure between the shoulder 59 and the dog 60a. This perm-its the latch 57 to be raised very easily and without the exertion of much force, so that the Bourdon tube 10 is not called upon to do any substantial amount of work and is. thus more sensitively responsive to pressure variations than it would otherwise be.

Vhile the device as herein illustrated in Fig. 4 is shown as operating indirectly to control the current through a pump or other motor, it is evident that the device 86 might be' dispensed with and that fthe current for the pump motor or other mechanism to be controlled might be carried directly through the conductors 5A and 6 and through the switch contacts 27 and 34. In many instances this arrangement would be permissible, although the arrangement shown in Fig. 4 may be found desirable when the dled is quite heavy.

While I have shown the invention as embodied in a specific construction, having parts 'of definite and predetermined shape and arranged in a. certain manner, I contemplate that many of the features of the invention might'well find embodiment in aspecilically different arrangement of parts and-I regard all such substitutions of parts and of equivalents as falling within the spirit of my invention.

I claim:

1.v A device of the class described comprising a circuit closing switch having relatively movable contacts, means tending to separate 'sa-id contacts, means comprising a p1voted latch normally holding the contacts in engagement, means providing an adjustable ulcrum for the latch, a. pressure responsive element,.and means connecting the pressure responsive element to the latch whereby to release the latch and to allow the contacts to separate at a predetermined pressure.

' 2. A device of the class described comprising a circuit closing switch having relatively movable contacts, means tending to separate said contacts, means comprising a pivoted latch normally holding the contacts in engagement, a pivoted support for the latch, means for adjusting' the latch support and for retaining it in adjusted position, and a pressure responsive element connected to the latch for releasing the latch to allow the rcontacts to separate at a predetermined pressure.

3. A device of the class described comp-rising a. pressure responsive element, a circuit closing switch having relatively movable contacts, means tending to separate the switch contacts, a retaining dog connected to one of the switch contacts, a holding latch normally engaging the dog to prevent separation of the contacts, means for transmitting move- Vment from the pressure responsive element to the latch to release the latch', andmeans for initially adjusting the latch with respect to the dog to determine the amount of movement of the. latch by the pressure responsive devices necessar to release the dog.

4. A device o the class described compris current to be 'haning a pressure responsive element, a circuit closing switch having relatively movable contacts, means tending to separate the switch contacts, a retaining dog connected to oneof the switch contacts, a holding latch normally engaging the dog to prevent separation of the contacts, a pivoted sup-port, a holding latch eccentrically fulcrumed on the support, said latch having a shoulder normally engaging the retaining dog, a link connecting the latch to the ressure responsive device, and means for ad] usting the pivoted latch support to vary the position of the latch fulcrum and thereby to vary the normal length of the line of contact between the latch shoulder -and the dog.

5. A device of the class described comprising an enclosing casing,a pressure responsive device therein, a. circuit closing switch having relatively movable contacts, means tending to separate the contacts, mechanical means comprising a. releasable latch normally holding the contacts in engagement, means transmitting movement of the pressure responsive element to thedlatch to release the latch and lallow the contacts to se a-ratc, and means accessible from the outsi e of the casing for adjusting the sition of the vfulcrum of said latch thus a justably determining the pressure at which the latch will be released.

6. A device of the class described comprising an enclosed casing, a pressure responsive device therein, a circuit closing switch having relatively movabley contacts, means tending to separate the contacts, a retaining dog conn'ected to one of the switch contacts, a holding latch normally engaging the dog to prevent separation of the contacts, means transmitting movement from the pressure responsive device to the latch to disengage the latch from the dog and thereby to permit separation of the switch contacts, Vand means accessible through an opening in the wall of the casing for in1tially adjusting the degree of engagement of the latch. with, the dog by adjusting the position of the fulcrum of the latch therelll!) llo by to determine the pressure at which the latch will disengage the dog.

7. A device of the class described comprising an enclosing casing, apressure respon- .sive device therein, a circuit closing switch having relatively'movable contacts, means tending to separate the contacts, a lever pivotall supported within'the casing, a bellcran latch pvotally supported upon said lever at a point spacedl Afrom the fulcrum of the latter, a spring tending to swing the' III to one of the switch contacts and normally engaged by the holding shoulder of the latch to prevent separation of the contacts.

8. A device of the class described comprising a pressure responsive element, a switch comprising a pair of separable contacts, one of said contacts being guided to slide in a rectilinear path and the other being movable in an arcuate path intersecting said rectilinear path, means tending to move said sliding contact toward the other contact, a latch for retaining said contacts in engagement, and meansactuable by the pressa re responsive element for releasing the latch.

9. A device of the class described coinprising a pressure responsive element, a switch comprising a pair of opposed movable contacts, said contacts being so supported that when one is pushed directly into contact with the other their engaging surfaces slide one on the other transversely to their direction of approach, a latch for retaining the contacts in engagement, and means actuable by the 4pressure responsive element for releasing the latch.

10. A device of the class described comprising a pressure responsive element, an electric switch comprising a pair of contacts, means tending to separate the contacts, a latch normally holding the contacts in engagement, means actuable by the pressure responsive element to release the latch, a lever pivoted to swing substantially in the plane of relative movement of the contacts, a barrier mounted upon the lever, a spring connected to the lever normally holding thebarrier to one side of a line connecting the contacts, and means moving in time with the contacts to move the lever. and thereby to introduce the barrier between the contacts as they separate.

11. A device of the class described comprising a pressure responsive element, a switch comprising a yieldable contact and a second contact movable toward and from the yielding contact, said contacts being movable in intersecting paths, means for moving the second contact into engagement with the first, a latch engageable on a slight further movement of the contacts in the general direction of motion of said second contact for retaining the second contact in engagement with the first, means for separating the contacts rwhen the latch is released, and means actuable by the pressure responsive element for releasing the latch, whereby the engaging surfaces of the contacts slide on the other transversely to their direction of approach when they are moved from their initial position of contact to the point where the latch is effective for holding them together.

12. A device of the above class described comprising a pressure responsive element, .a switch comprising normally engaging contacts, a pivoted lever supporting one of said contacts, a sliding carriage supporting the other contact, a spring urging the carriage in a direction to press its contact resiliently against the other, a manually operable device for swinging the switch lever to move its contact into engagement with the other,

a latch for retaining the switch lever in circuit closing position, and means actuable by the pressure responsive device to release its latch.

13. A device of the class described comprising a presssure responsive element, a switch comprising` normally engaging contacts, a lever supporting one of the contacts, means tending to swing the lever to separate the contacts, aI latch normally holding the lever in circuit closing position, means conncctingthe latch to the pressure responsive element, an insulating barrier for quenching the arc the contacts are separated, ay lever supporting the barrier, and an arm projecting from the switch lever and engaging said barrier supporting lever to swing the latter and thereby to in terpose the barrier between the contacts as the latter separate.

Signed by me at Bridgeport, Connecticut, this 24 day of August, 1925.

vOTTO HEISE. 

